Code

Merge branch 'jc/name' into next
[git.git] / diff.c
1 /*
2  * Copyright (C) 2005 Junio C Hamano
3  */
4 #include <sys/types.h>
5 #include <sys/wait.h>
6 #include <signal.h>
7 #include "cache.h"
8 #include "quote.h"
9 #include "diff.h"
10 #include "diffcore.h"
12 static const char *diff_opts = "-pu";
14 static int use_size_cache;
16 int diff_rename_limit_default = -1;
18 int git_diff_config(const char *var, const char *value)
19 {
20         if (!strcmp(var, "diff.renamelimit")) {
21                 diff_rename_limit_default = git_config_int(var, value);
22                 return 0;
23         }
25         return git_default_config(var, value);
26 }
28 static char *quote_one(const char *str)
29 {
30         int needlen;
31         char *xp;
33         if (!str)
34                 return NULL;
35         needlen = quote_c_style(str, NULL, NULL, 0);
36         if (!needlen)
37                 return strdup(str);
38         xp = xmalloc(needlen + 1);
39         quote_c_style(str, xp, NULL, 0);
40         return xp;
41 }
43 static char *quote_two(const char *one, const char *two)
44 {
45         int need_one = quote_c_style(one, NULL, NULL, 1);
46         int need_two = quote_c_style(two, NULL, NULL, 1);
47         char *xp;
49         if (need_one + need_two) {
50                 if (!need_one) need_one = strlen(one);
51                 if (!need_two) need_one = strlen(two);
53                 xp = xmalloc(need_one + need_two + 3);
54                 xp[0] = '"';
55                 quote_c_style(one, xp + 1, NULL, 1);
56                 quote_c_style(two, xp + need_one + 1, NULL, 1);
57                 strcpy(xp + need_one + need_two + 1, "\"");
58                 return xp;
59         }
60         need_one = strlen(one);
61         need_two = strlen(two);
62         xp = xmalloc(need_one + need_two + 1);
63         strcpy(xp, one);
64         strcpy(xp + need_one, two);
65         return xp;
66 }
68 static const char *external_diff(void)
69 {
70         static const char *external_diff_cmd = NULL;
71         static int done_preparing = 0;
72         const char *env_diff_opts;
74         if (done_preparing)
75                 return external_diff_cmd;
77         /*
78          * Default values above are meant to match the
79          * Linux kernel development style.  Examples of
80          * alternative styles you can specify via environment
81          * variables are:
82          *
83          * GIT_DIFF_OPTS="-c";
84          */
85         external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
87         /* In case external diff fails... */
88         env_diff_opts = getenv("GIT_DIFF_OPTS");
89         if (env_diff_opts) diff_opts = env_diff_opts;
91         done_preparing = 1;
92         return external_diff_cmd;
93 }
95 #define TEMPFILE_PATH_LEN               50
97 static struct diff_tempfile {
98         const char *name; /* filename external diff should read from */
99         char hex[41];
100         char mode[10];
101         char tmp_path[TEMPFILE_PATH_LEN];
102 } diff_temp[2];
104 static int count_lines(const char *filename)
106         FILE *in;
107         int count, ch, completely_empty = 1, nl_just_seen = 0;
108         in = fopen(filename, "r");
109         count = 0;
110         while ((ch = fgetc(in)) != EOF)
111                 if (ch == '\n') {
112                         count++;
113                         nl_just_seen = 1;
114                         completely_empty = 0;
115                 }
116                 else {
117                         nl_just_seen = 0;
118                         completely_empty = 0;
119                 }
120         fclose(in);
121         if (completely_empty)
122                 return 0;
123         if (!nl_just_seen)
124                 count++; /* no trailing newline */
125         return count;
128 static void print_line_count(int count)
130         switch (count) {
131         case 0:
132                 printf("0,0");
133                 break;
134         case 1:
135                 printf("1");
136                 break;
137         default:
138                 printf("1,%d", count);
139                 break;
140         }
143 static void copy_file(int prefix, const char *filename)
145         FILE *in;
146         int ch, nl_just_seen = 1;
147         in = fopen(filename, "r");
148         while ((ch = fgetc(in)) != EOF) {
149                 if (nl_just_seen)
150                         putchar(prefix);
151                 putchar(ch);
152                 if (ch == '\n')
153                         nl_just_seen = 1;
154                 else
155                         nl_just_seen = 0;
156         }
157         fclose(in);
158         if (!nl_just_seen)
159                 printf("\n\\ No newline at end of file\n");
162 static void emit_rewrite_diff(const char *name_a,
163                               const char *name_b,
164                               struct diff_tempfile *temp)
166         /* Use temp[i].name as input, name_a and name_b as labels */
167         int lc_a, lc_b;
168         lc_a = count_lines(temp[0].name);
169         lc_b = count_lines(temp[1].name);
170         printf("--- %s\n+++ %s\n@@ -", name_a, name_b);
171         print_line_count(lc_a);
172         printf(" +");
173         print_line_count(lc_b);
174         printf(" @@\n");
175         if (lc_a)
176                 copy_file('-', temp[0].name);
177         if (lc_b)
178                 copy_file('+', temp[1].name);
181 static const char *builtin_diff(const char *name_a,
182                          const char *name_b,
183                          struct diff_tempfile *temp,
184                          const char *xfrm_msg,
185                          int complete_rewrite,
186                          const char **args)
188         int i, next_at, cmd_size;
189         const char *const diff_cmd = "diff -L%s -L%s";
190         const char *const diff_arg  = "-- %s %s||:"; /* "||:" is to return 0 */
191         const char *input_name_sq[2];
192         const char *label_path[2];
193         char *cmd;
195         /* diff_cmd and diff_arg have 4 %s in total which makes
196          * the sum of these strings 8 bytes larger than required.
197          * we use 2 spaces around diff-opts, and we need to count
198          * terminating NUL; we used to subtract 5 here, but we do not
199          * care about small leaks in this subprocess that is about
200          * to exec "diff" anymore.
201          */
202         cmd_size = (strlen(diff_cmd) + strlen(diff_opts) + strlen(diff_arg)
203                     + 128);
205         for (i = 0; i < 2; i++) {
206                 input_name_sq[i] = sq_quote(temp[i].name);
207                 if (!strcmp(temp[i].name, "/dev/null"))
208                         label_path[i] = "/dev/null";
209                 else if (!i)
210                         label_path[i] = sq_quote(quote_two("a/", name_a));
211                 else
212                         label_path[i] = sq_quote(quote_two("b/", name_b));
213                 cmd_size += (strlen(label_path[i]) + strlen(input_name_sq[i]));
214         }
216         cmd = xmalloc(cmd_size);
218         next_at = 0;
219         next_at += snprintf(cmd+next_at, cmd_size-next_at,
220                             diff_cmd, label_path[0], label_path[1]);
221         next_at += snprintf(cmd+next_at, cmd_size-next_at,
222                             " %s ", diff_opts);
223         next_at += snprintf(cmd+next_at, cmd_size-next_at,
224                             diff_arg, input_name_sq[0], input_name_sq[1]);
226         printf("diff --git %s %s\n",
227                quote_two("a/", name_a), quote_two("b/", name_b));
228         if (label_path[0][0] == '/') {
229                 /* dev/null */
230                 printf("new file mode %s\n", temp[1].mode);
231                 if (xfrm_msg && xfrm_msg[0])
232                         puts(xfrm_msg);
233         }
234         else if (label_path[1][0] == '/') {
235                 printf("deleted file mode %s\n", temp[0].mode);
236                 if (xfrm_msg && xfrm_msg[0])
237                         puts(xfrm_msg);
238         }
239         else {
240                 if (strcmp(temp[0].mode, temp[1].mode)) {
241                         printf("old mode %s\n", temp[0].mode);
242                         printf("new mode %s\n", temp[1].mode);
243                 }
244                 if (xfrm_msg && xfrm_msg[0])
245                         puts(xfrm_msg);
246                 /*
247                  * we do not run diff between different kind
248                  * of objects.
249                  */
250                 if (strncmp(temp[0].mode, temp[1].mode, 3))
251                         return NULL;
252                 if (complete_rewrite) {
253                         emit_rewrite_diff(name_a, name_b, temp);
254                         return NULL;
255                 }
256         }
258         /* This is disgusting */
259         *args++ = "sh";
260         *args++ = "-c";
261         *args++ = cmd;
262         *args = NULL;
263         return "/bin/sh";
266 struct diff_filespec *alloc_filespec(const char *path)
268         int namelen = strlen(path);
269         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
271         memset(spec, 0, sizeof(*spec));
272         spec->path = (char *)(spec + 1);
273         memcpy(spec->path, path, namelen+1);
274         return spec;
277 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
278                    unsigned short mode)
280         if (mode) {
281                 spec->mode = DIFF_FILE_CANON_MODE(mode);
282                 memcpy(spec->sha1, sha1, 20);
283                 spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
284         }
287 /*
288  * Given a name and sha1 pair, if the dircache tells us the file in
289  * the work tree has that object contents, return true, so that
290  * prepare_temp_file() does not have to inflate and extract.
291  */
292 static int work_tree_matches(const char *name, const unsigned char *sha1)
294         struct cache_entry *ce;
295         struct stat st;
296         int pos, len;
298         /* We do not read the cache ourselves here, because the
299          * benchmark with my previous version that always reads cache
300          * shows that it makes things worse for diff-tree comparing
301          * two linux-2.6 kernel trees in an already checked out work
302          * tree.  This is because most diff-tree comparisons deal with
303          * only a small number of files, while reading the cache is
304          * expensive for a large project, and its cost outweighs the
305          * savings we get by not inflating the object to a temporary
306          * file.  Practically, this code only helps when we are used
307          * by diff-cache --cached, which does read the cache before
308          * calling us.
309          */
310         if (!active_cache)
311                 return 0;
313         len = strlen(name);
314         pos = cache_name_pos(name, len);
315         if (pos < 0)
316                 return 0;
317         ce = active_cache[pos];
318         if ((lstat(name, &st) < 0) ||
319             !S_ISREG(st.st_mode) || /* careful! */
320             ce_match_stat(ce, &st, 0) ||
321             memcmp(sha1, ce->sha1, 20))
322                 return 0;
323         /* we return 1 only when we can stat, it is a regular file,
324          * stat information matches, and sha1 recorded in the cache
325          * matches.  I.e. we know the file in the work tree really is
326          * the same as the <name, sha1> pair.
327          */
328         return 1;
331 static struct sha1_size_cache {
332         unsigned char sha1[20];
333         unsigned long size;
334 } **sha1_size_cache;
335 static int sha1_size_cache_nr, sha1_size_cache_alloc;
337 static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
338                                                  int find_only,
339                                                  unsigned long size)
341         int first, last;
342         struct sha1_size_cache *e;
344         first = 0;
345         last = sha1_size_cache_nr;
346         while (last > first) {
347                 int cmp, next = (last + first) >> 1;
348                 e = sha1_size_cache[next];
349                 cmp = memcmp(e->sha1, sha1, 20);
350                 if (!cmp)
351                         return e;
352                 if (cmp < 0) {
353                         last = next;
354                         continue;
355                 }
356                 first = next+1;
357         }
358         /* not found */
359         if (find_only)
360                 return NULL;
361         /* insert to make it at "first" */
362         if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
363                 sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
364                 sha1_size_cache = xrealloc(sha1_size_cache,
365                                            sha1_size_cache_alloc *
366                                            sizeof(*sha1_size_cache));
367         }
368         sha1_size_cache_nr++;
369         if (first < sha1_size_cache_nr)
370                 memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
371                         (sha1_size_cache_nr - first - 1) *
372                         sizeof(*sha1_size_cache));
373         e = xmalloc(sizeof(struct sha1_size_cache));
374         sha1_size_cache[first] = e;
375         memcpy(e->sha1, sha1, 20);
376         e->size = size;
377         return e;
380 /*
381  * While doing rename detection and pickaxe operation, we may need to
382  * grab the data for the blob (or file) for our own in-core comparison.
383  * diff_filespec has data and size fields for this purpose.
384  */
385 int diff_populate_filespec(struct diff_filespec *s, int size_only)
387         int err = 0;
388         if (!DIFF_FILE_VALID(s))
389                 die("internal error: asking to populate invalid file.");
390         if (S_ISDIR(s->mode))
391                 return -1;
393         if (!use_size_cache)
394                 size_only = 0;
396         if (s->data)
397                 return err;
398         if (!s->sha1_valid ||
399             work_tree_matches(s->path, s->sha1)) {
400                 struct stat st;
401                 int fd;
402                 if (lstat(s->path, &st) < 0) {
403                         if (errno == ENOENT) {
404                         err_empty:
405                                 err = -1;
406                         empty:
407                                 s->data = "";
408                                 s->size = 0;
409                                 return err;
410                         }
411                 }
412                 s->size = st.st_size;
413                 if (!s->size)
414                         goto empty;
415                 if (size_only)
416                         return 0;
417                 if (S_ISLNK(st.st_mode)) {
418                         int ret;
419                         s->data = xmalloc(s->size);
420                         s->should_free = 1;
421                         ret = readlink(s->path, s->data, s->size);
422                         if (ret < 0) {
423                                 free(s->data);
424                                 goto err_empty;
425                         }
426                         return 0;
427                 }
428                 fd = open(s->path, O_RDONLY);
429                 if (fd < 0)
430                         goto err_empty;
431                 s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
432                 close(fd);
433                 if (s->data == MAP_FAILED)
434                         goto err_empty;
435                 s->should_munmap = 1;
436         }
437         else {
438                 char type[20];
439                 struct sha1_size_cache *e;
441                 if (size_only) {
442                         e = locate_size_cache(s->sha1, 1, 0);
443                         if (e) {
444                                 s->size = e->size;
445                                 return 0;
446                         }
447                         if (!sha1_object_info(s->sha1, type, &s->size))
448                                 locate_size_cache(s->sha1, 0, s->size);
449                 }
450                 else {
451                         s->data = read_sha1_file(s->sha1, type, &s->size);
452                         s->should_free = 1;
453                 }
454         }
455         return 0;
458 void diff_free_filespec_data(struct diff_filespec *s)
460         if (s->should_free)
461                 free(s->data);
462         else if (s->should_munmap)
463                 munmap(s->data, s->size);
464         s->should_free = s->should_munmap = 0;
465         s->data = NULL;
466         free(s->cnt_data);
467         s->cnt_data = NULL;
470 static void prep_temp_blob(struct diff_tempfile *temp,
471                            void *blob,
472                            unsigned long size,
473                            const unsigned char *sha1,
474                            int mode)
476         int fd;
478         fd = git_mkstemp(temp->tmp_path, TEMPFILE_PATH_LEN, ".diff_XXXXXX");
479         if (fd < 0)
480                 die("unable to create temp-file");
481         if (write(fd, blob, size) != size)
482                 die("unable to write temp-file");
483         close(fd);
484         temp->name = temp->tmp_path;
485         strcpy(temp->hex, sha1_to_hex(sha1));
486         temp->hex[40] = 0;
487         sprintf(temp->mode, "%06o", mode);
490 static void prepare_temp_file(const char *name,
491                               struct diff_tempfile *temp,
492                               struct diff_filespec *one)
494         if (!DIFF_FILE_VALID(one)) {
495         not_a_valid_file:
496                 /* A '-' entry produces this for file-2, and
497                  * a '+' entry produces this for file-1.
498                  */
499                 temp->name = "/dev/null";
500                 strcpy(temp->hex, ".");
501                 strcpy(temp->mode, ".");
502                 return;
503         }
505         if (!one->sha1_valid ||
506             work_tree_matches(name, one->sha1)) {
507                 struct stat st;
508                 if (lstat(name, &st) < 0) {
509                         if (errno == ENOENT)
510                                 goto not_a_valid_file;
511                         die("stat(%s): %s", name, strerror(errno));
512                 }
513                 if (S_ISLNK(st.st_mode)) {
514                         int ret;
515                         char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
516                         if (sizeof(buf) <= st.st_size)
517                                 die("symlink too long: %s", name);
518                         ret = readlink(name, buf, st.st_size);
519                         if (ret < 0)
520                                 die("readlink(%s)", name);
521                         prep_temp_blob(temp, buf, st.st_size,
522                                        (one->sha1_valid ?
523                                         one->sha1 : null_sha1),
524                                        (one->sha1_valid ?
525                                         one->mode : S_IFLNK));
526                 }
527                 else {
528                         /* we can borrow from the file in the work tree */
529                         temp->name = name;
530                         if (!one->sha1_valid)
531                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
532                         else
533                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
534                         /* Even though we may sometimes borrow the
535                          * contents from the work tree, we always want
536                          * one->mode.  mode is trustworthy even when
537                          * !(one->sha1_valid), as long as
538                          * DIFF_FILE_VALID(one).
539                          */
540                         sprintf(temp->mode, "%06o", one->mode);
541                 }
542                 return;
543         }
544         else {
545                 if (diff_populate_filespec(one, 0))
546                         die("cannot read data blob for %s", one->path);
547                 prep_temp_blob(temp, one->data, one->size,
548                                one->sha1, one->mode);
549         }
552 static void remove_tempfile(void)
554         int i;
556         for (i = 0; i < 2; i++)
557                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
558                         unlink(diff_temp[i].name);
559                         diff_temp[i].name = NULL;
560                 }
563 static void remove_tempfile_on_signal(int signo)
565         remove_tempfile();
566         signal(SIGINT, SIG_DFL);
567         raise(signo);
570 static int spawn_prog(const char *pgm, const char **arg)
572         pid_t pid;
573         int status;
575         fflush(NULL);
576         pid = fork();
577         if (pid < 0)
578                 die("unable to fork");
579         if (!pid) {
580                 execvp(pgm, (char *const*) arg);
581                 exit(255);
582         }
584         while (waitpid(pid, &status, 0) < 0) {
585                 if (errno == EINTR)
586                         continue;
587                 return -1;
588         }
590         /* Earlier we did not check the exit status because
591          * diff exits non-zero if files are different, and
592          * we are not interested in knowing that.  It was a
593          * mistake which made it harder to quit a diff-*
594          * session that uses the git-apply-patch-script as
595          * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
596          * should also exit non-zero only when it wants to
597          * abort the entire diff-* session.
598          */
599         if (WIFEXITED(status) && !WEXITSTATUS(status))
600                 return 0;
601         return -1;
604 /* An external diff command takes:
605  *
606  * diff-cmd name infile1 infile1-sha1 infile1-mode \
607  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
608  *
609  */
610 static void run_external_diff(const char *pgm,
611                               const char *name,
612                               const char *other,
613                               struct diff_filespec *one,
614                               struct diff_filespec *two,
615                               const char *xfrm_msg,
616                               int complete_rewrite)
618         const char *spawn_arg[10];
619         struct diff_tempfile *temp = diff_temp;
620         int retval;
621         static int atexit_asked = 0;
622         const char *othername;
624         othername = (other? other : name);
625         if (one && two) {
626                 prepare_temp_file(name, &temp[0], one);
627                 prepare_temp_file(othername, &temp[1], two);
628                 if (! atexit_asked &&
629                     (temp[0].name == temp[0].tmp_path ||
630                      temp[1].name == temp[1].tmp_path)) {
631                         atexit_asked = 1;
632                         atexit(remove_tempfile);
633                 }
634                 signal(SIGINT, remove_tempfile_on_signal);
635         }
637         if (pgm) {
638                 const char **arg = &spawn_arg[0];
639                 if (one && two) {
640                         *arg++ = pgm;
641                         *arg++ = name;
642                         *arg++ = temp[0].name;
643                         *arg++ = temp[0].hex;
644                         *arg++ = temp[0].mode;
645                         *arg++ = temp[1].name;
646                         *arg++ = temp[1].hex;
647                         *arg++ = temp[1].mode;
648                         if (other) {
649                                 *arg++ = other;
650                                 *arg++ = xfrm_msg;
651                         }
652                 } else {
653                         *arg++ = pgm;
654                         *arg++ = name;
655                 }
656                 *arg = NULL;
657         } else {
658                 if (one && two) {
659                         pgm = builtin_diff(name, othername, temp, xfrm_msg, complete_rewrite, spawn_arg);
660                 } else
661                         printf("* Unmerged path %s\n", name);
662         }
664         retval = 0;
665         if (pgm)
666                 retval = spawn_prog(pgm, spawn_arg);
667         remove_tempfile();
668         if (retval) {
669                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
670                 exit(1);
671         }
674 static void diff_fill_sha1_info(struct diff_filespec *one)
676         if (DIFF_FILE_VALID(one)) {
677                 if (!one->sha1_valid) {
678                         struct stat st;
679                         if (lstat(one->path, &st) < 0)
680                                 die("stat %s", one->path);
681                         if (index_path(one->sha1, one->path, &st, 0))
682                                 die("cannot hash %s\n", one->path);
683                 }
684         }
685         else
686                 memset(one->sha1, 0, 20);
689 static void run_diff(struct diff_filepair *p, struct diff_options *o)
691         const char *pgm = external_diff();
692         char msg[PATH_MAX*2+300], *xfrm_msg;
693         struct diff_filespec *one;
694         struct diff_filespec *two;
695         const char *name;
696         const char *other;
697         char *name_munged, *other_munged;
698         int complete_rewrite = 0;
699         int len;
701         if (DIFF_PAIR_UNMERGED(p)) {
702                 /* unmerged */
703                 run_external_diff(pgm, p->one->path, NULL, NULL, NULL, NULL,
704                                   0);
705                 return;
706         }
708         name = p->one->path;
709         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
710         name_munged = quote_one(name);
711         other_munged = quote_one(other);
712         one = p->one; two = p->two;
714         diff_fill_sha1_info(one);
715         diff_fill_sha1_info(two);
717         len = 0;
718         switch (p->status) {
719         case DIFF_STATUS_COPIED:
720                 len += snprintf(msg + len, sizeof(msg) - len,
721                                 "similarity index %d%%\n"
722                                 "copy from %s\n"
723                                 "copy to %s\n",
724                                 (int)(0.5 + p->score * 100.0/MAX_SCORE),
725                                 name_munged, other_munged);
726                 break;
727         case DIFF_STATUS_RENAMED:
728                 len += snprintf(msg + len, sizeof(msg) - len,
729                                 "similarity index %d%%\n"
730                                 "rename from %s\n"
731                                 "rename to %s\n",
732                                 (int)(0.5 + p->score * 100.0/MAX_SCORE),
733                                 name_munged, other_munged);
734                 break;
735         case DIFF_STATUS_MODIFIED:
736                 if (p->score) {
737                         len += snprintf(msg + len, sizeof(msg) - len,
738                                         "dissimilarity index %d%%\n",
739                                         (int)(0.5 + p->score *
740                                               100.0/MAX_SCORE));
741                         complete_rewrite = 1;
742                         break;
743                 }
744                 /* fallthru */
745         default:
746                 /* nothing */
747                 ;
748         }
750         if (memcmp(one->sha1, two->sha1, 20)) {
751                 char one_sha1[41];
752                 int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
753                 memcpy(one_sha1, sha1_to_hex(one->sha1), 41);
755                 len += snprintf(msg + len, sizeof(msg) - len,
756                                 "index %.*s..%.*s",
757                                 abbrev, one_sha1, abbrev,
758                                 sha1_to_hex(two->sha1));
759                 if (one->mode == two->mode)
760                         len += snprintf(msg + len, sizeof(msg) - len,
761                                         " %06o", one->mode);
762                 len += snprintf(msg + len, sizeof(msg) - len, "\n");
763         }
765         if (len)
766                 msg[--len] = 0;
767         xfrm_msg = len ? msg : NULL;
769         if (!pgm &&
770             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
771             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
772                 /* a filepair that changes between file and symlink
773                  * needs to be split into deletion and creation.
774                  */
775                 struct diff_filespec *null = alloc_filespec(two->path);
776                 run_external_diff(NULL, name, other, one, null, xfrm_msg, 0);
777                 free(null);
778                 null = alloc_filespec(one->path);
779                 run_external_diff(NULL, name, other, null, two, xfrm_msg, 0);
780                 free(null);
781         }
782         else
783                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
784                                   complete_rewrite);
786         free(name_munged);
787         free(other_munged);
790 void diff_setup(struct diff_options *options)
792         memset(options, 0, sizeof(*options));
793         options->output_format = DIFF_FORMAT_RAW;
794         options->line_termination = '\n';
795         options->break_opt = -1;
796         options->rename_limit = -1;
798         options->change = diff_change;
799         options->add_remove = diff_addremove;
802 int diff_setup_done(struct diff_options *options)
804         if ((options->find_copies_harder &&
805              options->detect_rename != DIFF_DETECT_COPY) ||
806             (0 <= options->rename_limit && !options->detect_rename))
807                 return -1;
808         if (options->detect_rename && options->rename_limit < 0)
809                 options->rename_limit = diff_rename_limit_default;
810         if (options->setup & DIFF_SETUP_USE_CACHE) {
811                 if (!active_cache)
812                         /* read-cache does not die even when it fails
813                          * so it is safe for us to do this here.  Also
814                          * it does not smudge active_cache or active_nr
815                          * when it fails, so we do not have to worry about
816                          * cleaning it up ourselves either.
817                          */
818                         read_cache();
819         }
820         if (options->setup & DIFF_SETUP_USE_SIZE_CACHE)
821                 use_size_cache = 1;
822         if (options->abbrev <= 0 || 40 < options->abbrev)
823                 options->abbrev = 40; /* full */
825         return 0;
828 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
830         const char *arg = av[0];
831         if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
832                 options->output_format = DIFF_FORMAT_PATCH;
833         else if (!strcmp(arg, "-z"))
834                 options->line_termination = 0;
835         else if (!strncmp(arg, "-l", 2))
836                 options->rename_limit = strtoul(arg+2, NULL, 10);
837         else if (!strcmp(arg, "--full-index"))
838                 options->full_index = 1;
839         else if (!strcmp(arg, "--name-only"))
840                 options->output_format = DIFF_FORMAT_NAME;
841         else if (!strcmp(arg, "--name-status"))
842                 options->output_format = DIFF_FORMAT_NAME_STATUS;
843         else if (!strcmp(arg, "-R"))
844                 options->reverse_diff = 1;
845         else if (!strncmp(arg, "-S", 2))
846                 options->pickaxe = arg + 2;
847         else if (!strcmp(arg, "-s"))
848                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
849         else if (!strncmp(arg, "-O", 2))
850                 options->orderfile = arg + 2;
851         else if (!strncmp(arg, "--diff-filter=", 14))
852                 options->filter = arg + 14;
853         else if (!strcmp(arg, "--pickaxe-all"))
854                 options->pickaxe_opts = DIFF_PICKAXE_ALL;
855         else if (!strncmp(arg, "-B", 2)) {
856                 if ((options->break_opt =
857                      diff_scoreopt_parse(arg)) == -1)
858                         return -1;
859         }
860         else if (!strncmp(arg, "-M", 2)) {
861                 if ((options->rename_score =
862                      diff_scoreopt_parse(arg)) == -1)
863                         return -1;
864                 options->detect_rename = DIFF_DETECT_RENAME;
865         }
866         else if (!strncmp(arg, "-C", 2)) {
867                 if ((options->rename_score =
868                      diff_scoreopt_parse(arg)) == -1)
869                         return -1;
870                 options->detect_rename = DIFF_DETECT_COPY;
871         }
872         else if (!strcmp(arg, "--find-copies-harder"))
873                 options->find_copies_harder = 1;
874         else if (!strcmp(arg, "--abbrev"))
875                 options->abbrev = DEFAULT_ABBREV;
876         else if (!strncmp(arg, "--abbrev=", 9)) {
877                 options->abbrev = strtoul(arg + 9, NULL, 10);
878                 if (options->abbrev < MINIMUM_ABBREV)
879                         options->abbrev = MINIMUM_ABBREV;
880                 else if (40 < options->abbrev)
881                         options->abbrev = 40;
882         }
883         else
884                 return 0;
885         return 1;
888 static int parse_num(const char **cp_p)
890         unsigned long num, scale;
891         int ch, dot;
892         const char *cp = *cp_p;
894         num = 0;
895         scale = 1;
896         dot = 0;
897         for(;;) {
898                 ch = *cp;
899                 if ( !dot && ch == '.' ) {
900                         scale = 1;
901                         dot = 1;
902                 } else if ( ch == '%' ) {
903                         scale = dot ? scale*100 : 100;
904                         cp++;   /* % is always at the end */
905                         break;
906                 } else if ( ch >= '0' && ch <= '9' ) {
907                         if ( scale < 100000 ) {
908                                 scale *= 10;
909                                 num = (num*10) + (ch-'0');
910                         }
911                 } else {
912                         break;
913                 }
914                 cp++;
915         }
916         *cp_p = cp;
918         /* user says num divided by scale and we say internally that
919          * is MAX_SCORE * num / scale.
920          */
921         return (num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale);
924 int diff_scoreopt_parse(const char *opt)
926         int opt1, opt2, cmd;
928         if (*opt++ != '-')
929                 return -1;
930         cmd = *opt++;
931         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
932                 return -1; /* that is not a -M, -C nor -B option */
934         opt1 = parse_num(&opt);
935         if (cmd != 'B')
936                 opt2 = 0;
937         else {
938                 if (*opt == 0)
939                         opt2 = 0;
940                 else if (*opt != '/')
941                         return -1; /* we expect -B80/99 or -B80 */
942                 else {
943                         opt++;
944                         opt2 = parse_num(&opt);
945                 }
946         }
947         if (*opt != 0)
948                 return -1;
949         return opt1 | (opt2 << 16);
952 struct diff_queue_struct diff_queued_diff;
954 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
956         if (queue->alloc <= queue->nr) {
957                 queue->alloc = alloc_nr(queue->alloc);
958                 queue->queue = xrealloc(queue->queue,
959                                         sizeof(dp) * queue->alloc);
960         }
961         queue->queue[queue->nr++] = dp;
964 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
965                                  struct diff_filespec *one,
966                                  struct diff_filespec *two)
968         struct diff_filepair *dp = xmalloc(sizeof(*dp));
969         dp->one = one;
970         dp->two = two;
971         dp->score = 0;
972         dp->status = 0;
973         dp->source_stays = 0;
974         dp->broken_pair = 0;
975         if (queue)
976                 diff_q(queue, dp);
977         return dp;
980 void diff_free_filepair(struct diff_filepair *p)
982         diff_free_filespec_data(p->one);
983         diff_free_filespec_data(p->two);
984         free(p->one);
985         free(p->two);
986         free(p);
989 /* This is different from find_unique_abbrev() in that
990  * it stuffs the result with dots for alignment.
991  */
992 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
994         int abblen;
995         const char *abbrev;
996         if (len == 40)
997                 return sha1_to_hex(sha1);
999         abbrev = find_unique_abbrev(sha1, len);
1000         if (!abbrev)
1001                 return sha1_to_hex(sha1);
1002         abblen = strlen(abbrev);
1003         if (abblen < 37) {
1004                 static char hex[41];
1005                 if (len < abblen && abblen <= len + 2)
1006                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
1007                 else
1008                         sprintf(hex, "%s...", abbrev);
1009                 return hex;
1010         }
1011         return sha1_to_hex(sha1);
1014 static void diff_flush_raw(struct diff_filepair *p,
1015                            int line_termination,
1016                            int inter_name_termination,
1017                            struct diff_options *options)
1019         int two_paths;
1020         char status[10];
1021         int abbrev = options->abbrev;
1022         const char *path_one, *path_two;
1023         int output_format = options->output_format;
1025         path_one = p->one->path;
1026         path_two = p->two->path;
1027         if (line_termination) {
1028                 path_one = quote_one(path_one);
1029                 path_two = quote_one(path_two);
1030         }
1032         if (p->score)
1033                 sprintf(status, "%c%03d", p->status,
1034                         (int)(0.5 + p->score * 100.0/MAX_SCORE));
1035         else {
1036                 status[0] = p->status;
1037                 status[1] = 0;
1038         }
1039         switch (p->status) {
1040         case DIFF_STATUS_COPIED:
1041         case DIFF_STATUS_RENAMED:
1042                 two_paths = 1;
1043                 break;
1044         case DIFF_STATUS_ADDED:
1045         case DIFF_STATUS_DELETED:
1046                 two_paths = 0;
1047                 break;
1048         default:
1049                 two_paths = 0;
1050                 break;
1051         }
1052         if (output_format != DIFF_FORMAT_NAME_STATUS) {
1053                 printf(":%06o %06o %s ",
1054                        p->one->mode, p->two->mode,
1055                        diff_unique_abbrev(p->one->sha1, abbrev));
1056                 printf("%s ",
1057                        diff_unique_abbrev(p->two->sha1, abbrev));
1058         }
1059         printf("%s%c%s", status, inter_name_termination, path_one);
1060         if (two_paths)
1061                 printf("%c%s", inter_name_termination, path_two);
1062         putchar(line_termination);
1063         if (path_one != p->one->path)
1064                 free((void*)path_one);
1065         if (path_two != p->two->path)
1066                 free((void*)path_two);
1069 static void diff_flush_name(struct diff_filepair *p,
1070                             int inter_name_termination,
1071                             int line_termination)
1073         char *path = p->two->path;
1075         if (line_termination)
1076                 path = quote_one(p->two->path);
1077         else
1078                 path = p->two->path;
1079         printf("%s%c", path, line_termination);
1080         if (p->two->path != path)
1081                 free(path);
1084 int diff_unmodified_pair(struct diff_filepair *p)
1086         /* This function is written stricter than necessary to support
1087          * the currently implemented transformers, but the idea is to
1088          * let transformers to produce diff_filepairs any way they want,
1089          * and filter and clean them up here before producing the output.
1090          */
1091         struct diff_filespec *one, *two;
1093         if (DIFF_PAIR_UNMERGED(p))
1094                 return 0; /* unmerged is interesting */
1096         one = p->one;
1097         two = p->two;
1099         /* deletion, addition, mode or type change
1100          * and rename are all interesting.
1101          */
1102         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
1103             DIFF_PAIR_MODE_CHANGED(p) ||
1104             strcmp(one->path, two->path))
1105                 return 0;
1107         /* both are valid and point at the same path.  that is, we are
1108          * dealing with a change.
1109          */
1110         if (one->sha1_valid && two->sha1_valid &&
1111             !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
1112                 return 1; /* no change */
1113         if (!one->sha1_valid && !two->sha1_valid)
1114                 return 1; /* both look at the same file on the filesystem. */
1115         return 0;
1118 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
1120         if (diff_unmodified_pair(p))
1121                 return;
1123         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1124             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1125                 return; /* no tree diffs in patch format */ 
1127         run_diff(p, o);
1130 int diff_queue_is_empty(void)
1132         struct diff_queue_struct *q = &diff_queued_diff;
1133         int i;
1134         for (i = 0; i < q->nr; i++)
1135                 if (!diff_unmodified_pair(q->queue[i]))
1136                         return 0;
1137         return 1;
1140 #if DIFF_DEBUG
1141 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
1143         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
1144                 x, one ? one : "",
1145                 s->path,
1146                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
1147                 s->mode,
1148                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
1149         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
1150                 x, one ? one : "",
1151                 s->size, s->xfrm_flags);
1154 void diff_debug_filepair(const struct diff_filepair *p, int i)
1156         diff_debug_filespec(p->one, i, "one");
1157         diff_debug_filespec(p->two, i, "two");
1158         fprintf(stderr, "score %d, status %c stays %d broken %d\n",
1159                 p->score, p->status ? p->status : '?',
1160                 p->source_stays, p->broken_pair);
1163 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
1165         int i;
1166         if (msg)
1167                 fprintf(stderr, "%s\n", msg);
1168         fprintf(stderr, "q->nr = %d\n", q->nr);
1169         for (i = 0; i < q->nr; i++) {
1170                 struct diff_filepair *p = q->queue[i];
1171                 diff_debug_filepair(p, i);
1172         }
1174 #endif
1176 static void diff_resolve_rename_copy(void)
1178         int i, j;
1179         struct diff_filepair *p, *pp;
1180         struct diff_queue_struct *q = &diff_queued_diff;
1182         diff_debug_queue("resolve-rename-copy", q);
1184         for (i = 0; i < q->nr; i++) {
1185                 p = q->queue[i];
1186                 p->status = 0; /* undecided */
1187                 if (DIFF_PAIR_UNMERGED(p))
1188                         p->status = DIFF_STATUS_UNMERGED;
1189                 else if (!DIFF_FILE_VALID(p->one))
1190                         p->status = DIFF_STATUS_ADDED;
1191                 else if (!DIFF_FILE_VALID(p->two))
1192                         p->status = DIFF_STATUS_DELETED;
1193                 else if (DIFF_PAIR_TYPE_CHANGED(p))
1194                         p->status = DIFF_STATUS_TYPE_CHANGED;
1196                 /* from this point on, we are dealing with a pair
1197                  * whose both sides are valid and of the same type, i.e.
1198                  * either in-place edit or rename/copy edit.
1199                  */
1200                 else if (DIFF_PAIR_RENAME(p)) {
1201                         if (p->source_stays) {
1202                                 p->status = DIFF_STATUS_COPIED;
1203                                 continue;
1204                         }
1205                         /* See if there is some other filepair that
1206                          * copies from the same source as us.  If so
1207                          * we are a copy.  Otherwise we are either a
1208                          * copy if the path stays, or a rename if it
1209                          * does not, but we already handled "stays" case.
1210                          */
1211                         for (j = i + 1; j < q->nr; j++) {
1212                                 pp = q->queue[j];
1213                                 if (strcmp(pp->one->path, p->one->path))
1214                                         continue; /* not us */
1215                                 if (!DIFF_PAIR_RENAME(pp))
1216                                         continue; /* not a rename/copy */
1217                                 /* pp is a rename/copy from the same source */
1218                                 p->status = DIFF_STATUS_COPIED;
1219                                 break;
1220                         }
1221                         if (!p->status)
1222                                 p->status = DIFF_STATUS_RENAMED;
1223                 }
1224                 else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
1225                          p->one->mode != p->two->mode)
1226                         p->status = DIFF_STATUS_MODIFIED;
1227                 else {
1228                         /* This is a "no-change" entry and should not
1229                          * happen anymore, but prepare for broken callers.
1230                          */
1231                         error("feeding unmodified %s to diffcore",
1232                               p->one->path);
1233                         p->status = DIFF_STATUS_UNKNOWN;
1234                 }
1235         }
1236         diff_debug_queue("resolve-rename-copy done", q);
1239 void diff_flush(struct diff_options *options)
1241         struct diff_queue_struct *q = &diff_queued_diff;
1242         int i;
1243         int inter_name_termination = '\t';
1244         int diff_output_format = options->output_format;
1245         int line_termination = options->line_termination;
1247         if (!line_termination)
1248                 inter_name_termination = 0;
1250         for (i = 0; i < q->nr; i++) {
1251                 struct diff_filepair *p = q->queue[i];
1252                 if ((diff_output_format == DIFF_FORMAT_NO_OUTPUT) ||
1253                     (p->status == DIFF_STATUS_UNKNOWN))
1254                         continue;
1255                 if (p->status == 0)
1256                         die("internal error in diff-resolve-rename-copy");
1257                 switch (diff_output_format) {
1258                 case DIFF_FORMAT_PATCH:
1259                         diff_flush_patch(p, options);
1260                         break;
1261                 case DIFF_FORMAT_RAW:
1262                 case DIFF_FORMAT_NAME_STATUS:
1263                         diff_flush_raw(p, line_termination,
1264                                        inter_name_termination,
1265                                        options);
1266                         break;
1267                 case DIFF_FORMAT_NAME:
1268                         diff_flush_name(p,
1269                                         inter_name_termination,
1270                                         line_termination);
1271                         break;
1272                 }
1273                 diff_free_filepair(q->queue[i]);
1274         }
1275         free(q->queue);
1276         q->queue = NULL;
1277         q->nr = q->alloc = 0;
1280 static void diffcore_apply_filter(const char *filter)
1282         int i;
1283         struct diff_queue_struct *q = &diff_queued_diff;
1284         struct diff_queue_struct outq;
1285         outq.queue = NULL;
1286         outq.nr = outq.alloc = 0;
1288         if (!filter)
1289                 return;
1291         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
1292                 int found;
1293                 for (i = found = 0; !found && i < q->nr; i++) {
1294                         struct diff_filepair *p = q->queue[i];
1295                         if (((p->status == DIFF_STATUS_MODIFIED) &&
1296                              ((p->score &&
1297                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1298                               (!p->score &&
1299                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1300                             ((p->status != DIFF_STATUS_MODIFIED) &&
1301                              strchr(filter, p->status)))
1302                                 found++;
1303                 }
1304                 if (found)
1305                         return;
1307                 /* otherwise we will clear the whole queue
1308                  * by copying the empty outq at the end of this
1309                  * function, but first clear the current entries
1310                  * in the queue.
1311                  */
1312                 for (i = 0; i < q->nr; i++)
1313                         diff_free_filepair(q->queue[i]);
1314         }
1315         else {
1316                 /* Only the matching ones */
1317                 for (i = 0; i < q->nr; i++) {
1318                         struct diff_filepair *p = q->queue[i];
1320                         if (((p->status == DIFF_STATUS_MODIFIED) &&
1321                              ((p->score &&
1322                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1323                               (!p->score &&
1324                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1325                             ((p->status != DIFF_STATUS_MODIFIED) &&
1326                              strchr(filter, p->status)))
1327                                 diff_q(&outq, p);
1328                         else
1329                                 diff_free_filepair(p);
1330                 }
1331         }
1332         free(q->queue);
1333         *q = outq;
1336 void diffcore_std(struct diff_options *options)
1338         if (options->paths && options->paths[0])
1339                 diffcore_pathspec(options->paths);
1340         if (options->break_opt != -1)
1341                 diffcore_break(options->break_opt);
1342         if (options->detect_rename)
1343                 diffcore_rename(options);
1344         if (options->break_opt != -1)
1345                 diffcore_merge_broken();
1346         if (options->pickaxe)
1347                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1348         if (options->orderfile)
1349                 diffcore_order(options->orderfile);
1350         diff_resolve_rename_copy();
1351         diffcore_apply_filter(options->filter);
1355 void diffcore_std_no_resolve(struct diff_options *options)
1357         if (options->pickaxe)
1358                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1359         if (options->orderfile)
1360                 diffcore_order(options->orderfile);
1361         diffcore_apply_filter(options->filter);
1364 void diff_addremove(struct diff_options *options,
1365                     int addremove, unsigned mode,
1366                     const unsigned char *sha1,
1367                     const char *base, const char *path)
1369         char concatpath[PATH_MAX];
1370         struct diff_filespec *one, *two;
1372         /* This may look odd, but it is a preparation for
1373          * feeding "there are unchanged files which should
1374          * not produce diffs, but when you are doing copy
1375          * detection you would need them, so here they are"
1376          * entries to the diff-core.  They will be prefixed
1377          * with something like '=' or '*' (I haven't decided
1378          * which but should not make any difference).
1379          * Feeding the same new and old to diff_change() 
1380          * also has the same effect.
1381          * Before the final output happens, they are pruned after
1382          * merged into rename/copy pairs as appropriate.
1383          */
1384         if (options->reverse_diff)
1385                 addremove = (addremove == '+' ? '-' :
1386                              addremove == '-' ? '+' : addremove);
1388         if (!path) path = "";
1389         sprintf(concatpath, "%s%s", base, path);
1390         one = alloc_filespec(concatpath);
1391         two = alloc_filespec(concatpath);
1393         if (addremove != '+')
1394                 fill_filespec(one, sha1, mode);
1395         if (addremove != '-')
1396                 fill_filespec(two, sha1, mode);
1398         diff_queue(&diff_queued_diff, one, two);
1401 void diff_change(struct diff_options *options,
1402                  unsigned old_mode, unsigned new_mode,
1403                  const unsigned char *old_sha1,
1404                  const unsigned char *new_sha1,
1405                  const char *base, const char *path) 
1407         char concatpath[PATH_MAX];
1408         struct diff_filespec *one, *two;
1410         if (options->reverse_diff) {
1411                 unsigned tmp;
1412                 const unsigned char *tmp_c;
1413                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
1414                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
1415         }
1416         if (!path) path = "";
1417         sprintf(concatpath, "%s%s", base, path);
1418         one = alloc_filespec(concatpath);
1419         two = alloc_filespec(concatpath);
1420         fill_filespec(one, old_sha1, old_mode);
1421         fill_filespec(two, new_sha1, new_mode);
1423         diff_queue(&diff_queued_diff, one, two);
1426 void diff_unmerge(struct diff_options *options,
1427                   const char *path)
1429         struct diff_filespec *one, *two;
1430         one = alloc_filespec(path);
1431         two = alloc_filespec(path);
1432         diff_queue(&diff_queued_diff, one, two);